In Ramadan, the holiest Muslim month, jihad becomes a necessity. Instead of devoting time to worship and reciting the Quran, militant Muslims see the streets of London as full of evil and nudity. For them, all those non-Muslims are infidels and unbelievers, against whom jihad is prescribed, commendable, and supported by ancient sacred texts.

"...it is the duty of those who have accepted Islam to strive unceasingly to convert or subjugate those who have not. This obligation is without limit of time or space. It must continue until the whole world has either accepted the Islamic faith or submitted to the power of the Islamic state."

-- Bernard Lewis, renowned historian of Islam and the Middle East, in The Political Language of Islam, p72-3.

In other words:

"Islam is unique among religions of the world in having a developed doctrine, theology and legal system that mandates warfare against unbelievers."